Vauxhall Workshop Service and Repair Manuals

DTC P0111 - LLU

Diagnostic Instructions

DTC Descriptor

Diagnostic Fault Information

Typical Scan Tool Data

IAT Sensor

Circuit/System Description

The intake air temperature (IAT) sensor is a variable resistor. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The engine control module (ECM) supplies 5 V to the IAT signal circuit, and a ground for the IAT low reference circuit.

Conditions for Running the DTC

P0111 00

Conditions for Setting the DTC

P0111 00

The ECM detects that the IAT deviates less than 1.5°C (35°F) since engine start.

Action Taken When the DTC Sets

DTCs P0111 00 is a Type B DTC.

Conditions for Clearing the DTC

DTCs P0111 00 is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Air Inlet System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. If the ignition has been OFF for 8 h or greater, the B75B Mass Air Flow/Intake Air Temperature Sensor (IAT 1), the B65 Intake Manifold Pressure and Air Temperature Sensor (IAT 2) and the B34A Engine Coolant Temperature Sensor 1 should be within 9°C (16°F) of each other. Ignition ON, observe the scan tool IAT Sensor, IAT Sensor 2 and the ECT Sensor parameters. Compare those sensor parameters to each other to determine if the condition is current.
2. Engine running, observe the scan tool IAT Sensor parameter. The reading should be between -39 to +120°C (-38 to +248°F) depending on the current ambient temperature and the vehicle operating conditions.
3. Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the B75B Mass Air Flow/Intake Air Temperature Sensor.
2. Ignition OFF for 90 s, test for less than 5 Ω between the ground circuit terminal 2 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, test for 4.8-5.2 V between the B75B Mass Air Flow/Intake Air Temperature Sensor (IAT 1) low reference circuit terminal 3 and ground.

⇒	If less than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

4. Ignition ON, verify the scan tool IAT Sensor parameter is colder than -39°C (-38°F).

⇒	If warmer than the specified range, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module.

5. Install a 3 A fused jumper wire between the B75B Mass Air Flow/Intake Air Temperature Sensor signal circuit terminal 3 and the low reference terminal 1. Verify the scan tool IAT Sensor parameter is warmer than 142°C (288°F).

⇒	If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal replace the K20 Engine Control Module.

6. If all circuits/connections test normal, replace the B75B Mass Air Flow/ Inlet Air Temperature Sensor.

Component Testing

Static Test

Measure and record the resistance of the B75B Mass Air Flow/Intake Air Temperature Sensor (IAT 1) at various ambient temperatures, then compare those measurements to the Temperature Versus Resistance table.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.